Home > Publications database > Untersuchungen zur Biosynthese von Biarylnaturstoffen in dem filamentösen Pilz $\textit{Penicillium citreo-viride}$ |
Dissertation / PhD Thesis/Book | PreJuSER-29122 |
2003
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
Jülich
Please use a persistent id in citations: http://hdl.handle.net/2128/126
Report No.: Juel-4117
Abstract: Biaryl compounds are very interesting synthetic targets in organic chemistry because of their multifaceted properties as pharmacologically active natural products or chiral reagents. The awarding of the Nobel Prize to Ryoji Noyori in 2001 has highlighted the impact of this class of compounds. Often, the chemical synthesis of naturally occurring biaryl compounds is very complex. In nature, these natural products are biosynthesized in one single step, which involves radical intermediates. The biaryl compounds produced by this oxidative phenolic coupling exhibit a regio- and stereochemistry characteristic for their individual biological origin. To investigate the biosynthesis an interdisciplinary approach between organic chemistry and microbiology was chosen. At first, a protocol for the reproducible cultivation of the model organism $\textit{Penicillium citreo-viride}$ was elaborated which enabled the isolation of secondary metabolites, the development of an analytical assay and the performance of feeding experiments. It could be shown that the monomeric precursor $\textit{semi}$-Vioxanthin is metabolized completely during fermentation and only biaryl natural products are present in the mycelium of the fungus. [...] The chemical work dealt with the total synthesis the natural products semi-Vioxanthin and Vioxanthin. Thereby, several strategies for the synthesis of biaryl compounds were developed. A novel unselective oxidative phenolic coupling of orsellinates with ferric chloride was established which furnished all three possible regioisomeric coupling products in overall yields of 70 %. In preparation for further molecular biological work an innovative screening for lipases was developed which bases on the chiroptical method of circular dichroism.
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